R factors mediate resistance to mercury, nickel, and cobalt.
Fifty-five clinical isolates and laboratory stocks of Escherichia coli and Salmonella were studied for resistance to each of ten metals. Eleven clinical isolates carrying R factors were resistant to mercury, and, in each case, the resistance was mediated by a previously undefined R-factor gene. The gene was phenotypically expressed within 2 to 4 minutes after entry into sensitive bacteria, but the basis for the resistance remains undefined. Fourteen strains, 12 infected with R factors, were resistant to cobalt and nickel, but these resistances were mediated by R-factor genes in only two strains; separate R-factor genes mediated the resistances to nickel and cobalt. These and other results indicate that the genetic composition of R factors is greater than that originally defined.
D003035:Cobalt; D004352:Drug Resistance, Microbial; D004926:Escherichia coli; D005796:Genes; D008628:Mercury; D009532:Nickel; D010597:Pharmacogenetics; D012486:Salmonella typhimurium
D003035:Cobalt; D009532:Nickel; D008628:Mercury